Finfets having step sided contact plugs and methods of manufacturing the same

ABSTRACT

A semiconductor device includes an active fin extending in a first direction on a substrate, a gate electrode intersecting the active fin and extending in a second direction, source/drain regions disposed on the active fin on both sides of the gate electrode, and a contact plug disposed on the source/drain regions. The contact plug has at least one side extending in the second direction which has a step portion having a step shape.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/560,353, filed Dec. 23, 2021, which is a continuation of U.S. patentapplication Ser. No. 16/794,326, filed Feb. 19, 2020, now U.S. Pat. No.11,211,490, which is a continuation of U.S. patent application Ser. No.14/989,646, filed Jan. 6, 2016, now U.S. Pat. No. 10,686,073, whichclaims the priority and benefit of Korean Patent Application No.10-2015-0029162, filed Mar. 2, 2015, with the Korean IntellectualProperty Office, the disclosures of which are incorporated herein byreference.

BACKGROUND

The present inventive concepts relate to a semiconductor device and amethod of manufacturing the same.

As demand for high performance, high speed, and/or multiple functionsand the like of semiconductor devices increases, the degree ofintegration of semiconductor devices has similarly risen. In themanufacturing of semiconductor devices having a fine patterncorresponding to higher integration trends in semiconductor devices,implementing patterns having a fine width or spacing are desired.Furthermore, in order to overcome the limitations of elementcharacteristics of a planar metal oxide semiconductor FET (MOSFET),efforts to develop semiconductor devices which include FinFETs providedwith a three-dimensional channel structure are underway.

SUMMARY

According to an aspect of the present inventive concepts, asemiconductor device may include an active fin extending in a firstdirection on a substrate, a gate electrode intersecting the active finand extending in a second direction that is different from the firstdirection, a source/drain region disposed on the active fin on bothsides of the gate electrode, and a contact plug disposed on thesource/drain region on one side of the gate electrode and extending inthe second direction. The contact plug has a side extending in thesecond direction which has a step portion having a step shape.

In other embodiments, the contact plug side has a plurality of linesegments when viewed in cross-section.

The step portion may be located outwardly of the source/drain region onthe one side of the gate electrode in the second direction.

The side of the contact plug may have a step surface extending parallelto an upper surface of the substrate by the step portion.

The side of the contact plug in the upper and lower portions of the stepsurface may have a gradient with respect to the upper surface of thesubstrate.

The semiconductor device may further include a first interlayerinsulating layer on, and in some embodiments covering, the gateelectrode and the source/drain regions, and a second interlayerinsulating layer on the first interlayer insulating layer. The stepsurface may be located within the second interlayer insulating layer.

The first interlayer insulating layer may comprise a tonen silazene(TOZ) film, and the second interlayer insulating layer may comprise atetraethyl ortho silicate (TEOS) film.

The contact plug may have an elongated shape extending in the seconddirection.

The contact plug may have a first length in the first direction and asecond length in the second direction. The second length may be three ormore times greater than the first length.

The contact plug may include a first region in a lower portion of thecontact plug and a second region on the first region. The step portionmay be provided by the second region extending to be longer than thefirst region in the second direction.

The contact plug may be on, and in some embodiments may cover, at leastportions of upper and side surfaces of the source/drain regions on theone side of the gate electrode.

Both sides of the contact plug extending in the second direction mayhave the step portions.

The step portions in both sides of the contact plug may narrow towardthe substrate.

The step portion in one side of the contact plug may narrow toward thesubstrate and the step portion in the other side of the contact plug maywiden toward the substrate.

One side of the contact plug may have a plurality of step portions.

Two or more of the active fins may be disposed adjacent to each other inthe second direction, and the gate electrode may intersect the two ormore of the active fins. The semiconductor device further comprises asource/drain region disposed on each of the active fins on both sides ofthe gate electrode.

The source/drain regions may have a structure in which the source/drainregions are connected to each other on two or more of the active fins.

The active fin may include recessed regions on both sides of the gateelectrode, and the source/drain regions may be disposed in the recessedregions.

The source/drain regions may include a silicon germanium (SiGe)epitaxial layer.

The semiconductor device may further include a wiring line connected tothe contact plug on the contact plug, and the wiring line may bedisposed on the side of the contact plug having the step portion.

Two of the contact plugs may be disposed on both sides of the gateelectrode, respectively, and may be connected to two of the wiring linesdifferent from each other, respectively. The step portions on therespective contact plugs may be located on different sides of thecontact plugs.

According to another aspect of the present inventive concepts, asemiconductor device may include a substrate having an active region, agate electrode on the active region to cross the active region,source/drain regions on the active region and elevated from thesubstrate, and a contact plug on, and in some embodiments covering,portions of an upper surface and a side of the source/drain regions, andhaving at least one side which has a step portion having a step shapeabove the source/drain regions.

The step portion may be located on the side of the contact plug in adirection of the gate electrode extending and intersecting the activeregion.

The semiconductor device may further include a wiring line disposed onthe side of the contact plug having the step portions, connected to thecontact plug, and extending in a direction parallel to the activeregion.

According to another aspect of the present inventive concepts, asemiconductor device may include a substrate with an active region, agate electrode on the active region to cross the active region,source/drain regions on the active region and elevated from thesubstrate, and a contact plug on the source/drain regions and having anasymmetrical shape in a direction of the gate electrode extending andintersecting the active region.

According to another aspect of the present inventive concepts, a methodof manufacturing a semiconductor device may include defining an activefin extending in a first direction on a substrate, forming a gateelectrode extending in a second direction that is different from thefirst direction and intersecting the active fin, forming a source/drainregion disposed on the active fin on both sides of the gate electrode,and forming a contact plug disposed on one of the source/drain regionsand having at least one side extending in the second direction which hasa step portion having a step shape.

The forming of the contact plug may include forming an interlayerinsulating layer on, and in some embodiments covering, the source/drainregions, a first patterning operation removing a portion of theinterlayer insulating layer using a first mask layer having a first openregion on the source/drain regions, a second patterning operationremoving a portion of the interlayer insulating layer using a secondmask layer having a second open region on the source/drain regions thatis different in size than the first open region, and providing aconductive material in, and in some embodiments filling, a regionremoved of the interlayer insulating layer.

The first and second open regions may be at least partially overlapped.

The second open region may include the first open region, and may beformed to be expanded further than the first open region on at least oneside. The step portion may be formed in a region where the first andsecond open regions do not overlap.

The forming of the contact plug may include forming a first interlayerinsulating layer on, and in some embodiments covering, the source/drainregions, a first patterning operation removing a portion of the firstinterlayer insulating layer using a first mask layer on the source/drainregions, forming a first region of the contact plug in, and in someembodiments by filling, a region removed of the first interlayerinsulating layer with a conductive material, forming a second interlayerinsulating layer on, and in some embodiments covering, the first region,a second patterning operation removing a portion of the secondinterlayer insulating layer using a second mask layer on thesource/drain regions, and forming a second region of the contact plugin, and in some embodiments by filling, a region removed of the secondinterlayer insulating layer with a conductive material.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features and advantages of the presentinventive concepts will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIGS. 1 and 2 are a plan view and a perspective view illustrating asemiconductor device according to example embodiments of the presentinventive concepts;

FIGS. 3A and 3B are cross-sectional views taken along line A-A′ and lineB-B′ of the semiconductor device of FIG. 2 ;

FIGS. 4 to 7 are cross-sectional views illustrating a semiconductordevice according to example embodiments of the present inventiveconcepts;

FIGS. 8 and 9 are perspective views illustrating a semiconductor deviceaccording to example embodiments of the present inventive concepts;

FIGS. 10 to 22B are views illustrating a process sequence to illustratea method of manufacturing a semiconductor device according to exampleembodiments of the present inventive concepts;

FIGS. 23 to 26 are views illustrating a process sequence to illustrate amethod of manufacturing a semiconductor device according to exampleembodiments of the present inventive concepts;

FIGS. 27 to 28B are a plan view and cross-sectional views of asemiconductor device according to example embodiments of the presentinventive concepts;

FIG. 29 is a circuit diagram of an SRAM cell including a semiconductordevice according to example embodiments of the present inventiveconcepts;

FIG. 30 is a block diagram illustrating a storage device including asemiconductor device according to example embodiments of the presentinventive concepts;

FIG. 31 is a block diagram illustrating an electronic apparatusincluding a semiconductor device according to example embodiments of thepresent inventive concepts; and

FIG. 32 is a schematic diagram illustrating a system including asemiconductor device according to example embodiments of the presentinventive concepts.

DETAILED DESCRIPTION

Hereinafter, example embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Thedisclosure may, however, be exemplified in many different forms andshould not be construed as being limited to the specific exampleembodiments set forth herein. Rather, these example embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the disclosure to those skilled in the art.

In the drawings, the shapes and dimensions of elements may beexaggerated for clarity, and the same reference numerals will be usedthroughout to designate the same or like elements.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” to another element, it can be directly connected to theother element or intervening elements may be present. In contrast, whenan element is referred to as being “directly connected” to anotherelement, there are no intervening elements present. Other words used todescribe the relationship between elements should be interpreted in alike fashion (e.g., “between” versus “directly between”, “adjacent”versus “directly adjacent”, etc.).

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer or region to another element, layer or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention.The thickness of layers and regions in the drawings may be exaggeratedfor clarity. Additionally, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, embodiments of theinvention should not be construed as limited to the particular shapes ofregions illustrated herein but are to include deviations in shapes thatresult, for example, from manufacturing.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”“comprising,” “includes”, “including”, “have” and/or “having (andvariants thereof) when used herein, specify the presence of statedelements or steps but do not preclude the presence or addition of one ormore other elements or steps.

FIGS. 1 and 2 are a plan view and a perspective view, respectively,illustrating a semiconductor device according to example embodiments ofthe present inventive concepts. FIGS. 3A and 3B are cross-sectionalviews taken along line A-A′ and line B-B′ of a semiconductor device ofFIG. 2 . For convenience of description, FIG. 1 illustrates only themajor configuring elements, and FIG. 2 is illustrated omitting first andsecond interlayer insulating layers 162 and 164.

Referring to FIGS. 1 to 3B, a semiconductor device 100 may include asubstrate 101, active fins 105, source/drain regions 110, a gatestructure 140, contact plugs 170F and 170S, and wiring lines 180F and180S. The semiconductor device 100 may further include isolation layers107 and first and second interlayer insulating layers 162 and 164.

The semiconductor device 100 in the example embodiment of the presentinventive concepts may be provided as a FinFET with the active fins 105having a fin structure.

The substrate 101 may have an upper surface extending in x and ydirections. The substrate 101 may include a semiconductor material suchas a group IV semiconductor material, a group III-V compoundsemiconductor material and/or a group II-VI semiconductor material. Forexample, a group IV semiconductor material may include silicon,germanium and/or silicon-germanium. The substrate 101 may be provided asa bulk wafer, an epitaxial layer, a Silicon-on-Insulator (SOI) layer, aSemiconductor-on-Insulator (SeOI) layer, or the like.

The isolation layers 107 may define the active fins 105 in the substrate101. The isolation layers 107 may contain an insulating material. Theisolation layers 107 may be, for example, formed by a shallow trenchelement isolation (STI) process. The isolation layers 107 may be, forexample, oxides, nitrides, or combinations thereof.

The active fins 105 may be defined by the isolation layers 107 in thesubstrate 101, and may be disposed to be extended in a first direction,for example, in the y-direction. The active fins 105 may have an activefin structure protruding from the substrate 101. The active fins 105 maybe formed by a portion of the substrate 101 and may include an epitaxiallayer grown from the substrate 101. However, on both sides of the gatestructure 140, the active fins 105 on the substrate 101 may be partiallyremoved and the source/drain regions 110 may be disposed.

The source/drain regions 110 may be disposed on the active fins 105 onboth sides of the gate structure 140. The source/drain regions 110 maybe provided as source regions or drain regions of the semiconductordevice 100. The source/drain regions 110 may be in an elevatedsource/drain form in which the upper surface thereof is located higherthan the lower surface of the gate structure 140. In the exampleembodiment of the present inventive concepts, the source/drain regions110 are illustrated in a pentagonal shape, but the source/drain regions110 may have various shapes such as any one of a polygonal, circular, orrectangular shape. Further, in the example embodiment of the presentinventive concepts, the source/drain regions 110 are illustrated ashaving a structure of being connected to each other or merged togetheron the three active fins 105, but are not limited thereto. Thesource/drain regions 110 may include, for example, silicon and/orsilicon germanium (SiGe).

The gate structure 140 may be disposed so as to intersect the activefins 105 on the upper portion of the active fins 105, and may include agate insulating layer 142, first and second gate electrodes 145 and 147,and a spacer 144.

The gate insulating layer 142 may be disposed between the active fins105 and the first and second gate electrodes 145 and 147. The gateinsulating layer 142 may include an oxide, a nitride and/or a high-kdielectric (high-k) material. The high-k material may indicate adielectric material having a higher dielectric constant than that ofsilicon dioxide (SiO₂). The high-k material may be, for example, any oneor more of aluminum oxide (Al₂O₃), tantalum oxide (Ta₂O₃), titaniumoxide (TiO₂), yttrium oxide (Y₂O₃), zirconium oxide (ZrO₂), zirconiumsilicon oxide (ZrSi_(x)O_(y)), hafnium oxide (HfO₂), hafnium siliconoxide (HfSi_(x)O_(y)), lanthanum oxide (La₂O₃), lanthanum aluminum oxide(LaAl_(x)O_(y)), hafnium lanthanum oxides (LaHf_(x)O_(y)), hafniumaluminum oxide (HfAl_(x)O_(y)), or praseodymium oxide (Pr₂O₃). Inanother example embodiment of the present inventive concepts, the gateinsulating layer 142 may be formed only on a lower portion of the firstand second gate electrodes 145 and 147.

The first and second gate electrodes 145 and 147 may be sequentiallydisposed on the gate insulating layer 142. When the semiconductor device100 is a transistor, a channel region may be formed in the active fins105 intersecting the first and second gate electrodes 145 and 147. Thefirst and second gate electrodes 145 and 147 may be formed of differentmaterials from each other. The first gate electrode 145 may include, forexample, a metal nitride such as titanium nitride (TiN), tantalumnitride (TaN) and/or tungsten nitride (WN). The second gate electrode147 may include, for example, a metal material such as aluminum (Al),tungsten (W), molybdenum (Mo) and/or the like, and/or a semiconductormaterial such as doped polysilicon. The first gate electrode 145 mayserve as a diffusion barrier layer for the second gate electrode 147,but is not limited thereto. In another example embodiment of the presentinventive concepts, the gate electrode may be formed of a single layer.

The spacer 144 may be disposed on the gate insulating layer 142 on bothsides of the first and second gate electrodes 145 and 147. The spacer144 may isolate the source/drain regions 110 from the first and secondgate electrodes 145 and 147. The spacer 144 may be formed using anoxide, a nitride, or an oxynitride, and may also be configured of amultilayer film.

The contact plugs 170F and 170S may be disposed on the source/drainregions 110, and may electrically connect the source/drain regions 110and the wiring lines 180F and 180S. The contact plugs 170F and 170S maypenetrate the first and second interlayer insulating layers 162 and 164,but are not limited thereto.

Referring to FIG. 1 , one ends of the contact plugs 170F and 170S may beextended outwardly by a first length L1 from one ends of thesource/drain regions 110, respectively. The other ends of the contactplugs 170F and 170S may be extended by a second length L2, which is lessthan the first length L1, from the other ends of the source/drain region110, respectively. According to example embodiments of the presentinventive concepts, the first and second lengths L1 and L2 may bechanged in various ways. However, the first length L1 may be determinedso that the contact plugs 170F and 170S may be connected to the wiringlines 180F and 180S located on one sides of the source/drain regions110, respectively.

The contact plugs 170F and 170S may have elongated shapes. For example,the contact plugs 170F and 170S may have a shape extending in anextended direction of the gate structure 140, for example, in anx-direction, and may have a rectangular, an oval shape and/or the like.A third length L3, a length in a y direction, may be less than a fourthlength L4, a length in the x-direction; for example, the fourth lengthL4 may be more than three times the third length L3.

Referring to FIGS. 2 and 3A, both sides of the contact plugs 170F and/or170S in the x-direction may have an asymmetric shape on the upperportion of the source/drain regions 110. For example, the contact plugmay have a vertical or an inclined side on the source/drain regions 110,and the other side thereof may have a step portion ST having a stepshape. As used herein, a “step portion” may refer to an area of adrastically differing width between a top portion and a bottom portionof the contact plugs extending in a single direction with differentlengths. The step portion ST may be located outwardly of thesource/drain regions 110. The contact plugs 170F and 170S may bestep-shaped in reverse toward the substrate 101 with a narrowing widthtoward the substrate 101 by the step portion ST of the exampleembodiment of the present inventive concepts. However, in the presentspecification, unless specified otherwise, the term “step-shaped” may beused to refer to all of a step shape and a step shape in reverse towardthe substrate 101. The step portions ST formed in the sides of thecontact plugs 170F and 170S may be located in the side surfaces thereofprovided in different directions with respect to each other. Thus, thecontact plugs 170F and 170S may be stably coupled respectively to thewiring lines 180F and 180S. The contact plugs 170F and 170S may also beregarded as having at least one side that comprises a plurality of linesegments LS, when viewed in cross-section.

The contact plugs 170F and 170S may include a first region on thesource/drain regions 110, and a second region having a width wider thanthe first region on the first region. At an interface of the first andsecond regions, a step surface SP in which the second region is extendedto be longer than the first region by a fifth length L5 may be formed.The step surface SP may be located within the second interlayerinsulating layer 164, whereby a parasitic capacitance between thecontact plugs 170F and 170S and the first and the second gate electrodes145 and 147 may be significantly lessened. However, the location of thestep surface SP is not limited thereto, and in an example embodiment ofthe present inventive concepts, the step surface SP may also be locatedwithin the first interlayer insulating layer 162.

On sides of the contact plugs 170F and 170S having step portions (ST),the first region may have a side having a gradient of a first angle θ1with respect to a direction perpendicular to the substrate 101, and thesecond region may have a side having a gradient of a second angle θ2.The first and second angles θ1 and θ2 may be the same as or differentfrom each other. The step portion ST may refer to a region including thestep surface SP and upper and lower portions of the step surface SPperpendicular or inclined to the step surface SP. The step surface SPmay be located outwardly of the source/drain regions 110 in thex-direction and may be parallel to the upper surface of the substrate101, or may have a gradient. The fifth length L5 may be determined inconsideration of the distance between the source/drain regions 110 andthe wiring lines 180F and 180S, and the gradient of the sides of thecontact plugs 170F and 170S.

The contact plugs 170F and 170S may be on, and in some embodiments maycover, a portion of the upper surface of the source/drain regions 110.For example, the contact plugs 170F and 170S may cover the entire uppersurface of the source/drain regions 110 on a cross section in an x-zdirection as in FIG. 3A. Further, the contact plugs 170F and 170S maycover at least portions of the upper and side surfaces of thesource/drain regions 110. In the example embodiment of the presentinventive concepts, the contact plugs 170F and 170S may cover at leasttwo surfaces of the respective pentagonal areas forming the source/drainregions 110. The contact plugs 170F and 170S may be spaced apart byfirst and second distances D1 and D2 respectively from both ends of thesource/drain regions 110, but are not limited thereto. The first andsecond distances D1 and D2 may be the same as or different from eachother, or may be zero. In another example embodiment of the presentinventive concepts, the contact plugs 170F and 170S may cover the endportions of the source/drain regions 110 and may be extended to thelower portion thereof.

The contact plugs 170F and 170S may include a barrier layer BM and aconductive layer CM. The barrier layer BM may function as a diffusionbarrier layer on a metal material forming the conductive layer CM. Thebarrier layer BM may be formed along the upper portion of thesource/drain regions 110, the side walls of the contact plugs 170F and170S, and the step surface SP. The barrier layer BM may include, forexample, at least one metal nitride among titanium nitride (TiN),tantalum nitride (TaN) and/or tungsten nitride film (WN). The conductivelayer CM may include a conductive material such as aluminum (Al), copper(Cu), tungsten (W) and/or molybdenum (Mo).

The first and second interlayer insulating layers 162 and 164 may bedisposed on, and in some embodiments to cover, the substrate 101, thesource/drain regions 110, and the gate structure 140. A height H1 of thefirst interlayer insulating layer 162 may be substantially the same as aheight of the gate structure 140. However, as the first and secondinterlayer insulating layers 162 and 164 may be layers formed in thedifferent process steps, relative heights and relative locations thereofwith respect to the step surface SP are not limited to those illustratedin the drawings. In another example embodiment of the present inventiveconcepts, the first and second interlayer insulating layers 162 and 164may be formed of a single layer. The first and second interlayerinsulating layers 162 and 164 may be formed of an insulating material,and may include at least one of an oxide film, a nitride film, and/or anoxynitride film. For example, the first interlayer insulating layer 162may be provided as a tonen silazene (TOZ) film, and the secondinterlayer insulating layer 164 may be a tetraethyl ortho silicate(TEOS) film.

The wiring lines 180F and 180S may be disposed to be connected to thecontact plugs 170F and 170S. Referring to FIGS. 1 and 3A, the wiringlines 180F and 180S may be located on upper portions of one side of thecontact plugs 170F and 170S, and may be contacted therewith by a sixthlength L6. The sixth length L6 may be determined in consideration of thethird length L3, which is the width of the contact plugs 170F and 170S,the resistance of the contact plugs 170F and 170S, and the like. Thewiring lines 180F and 180S may include a conductive material such asaluminum (Al), copper (Cu) and/or tungsten (W), and the like.

FIGS. 4 to 7 are cross-sectional views illustrating a semiconductordevice according to example embodiments of the present inventiveconcepts. FIGS. 4 to 7 illustrate cross sections corresponding to FIG.3A.

Referring to FIG. 4 , a semiconductor device 100 a may include asubstrate 101, active fins 105, source/drain regions 110, a gatestructure 140, a contact plug 170Fa, and a wiring line 180F. Thesemiconductor device 100 a may further include isolation layers 107, andan interlayer insulating layer 160.

The contact plug 170Fa may be disposed on the source/drain regions 110,and may electrically connect the source/drain regions 110 and the wiringline 180F. The contact plug 170Fa may penetrate the interlayerinsulating layer 160. In example embodiments of the present inventiveconcepts below, the contact plug 170Fa is illustrated in a simplifiedform, but as in the example embodiments of the present inventiveconcepts in FIGS. 3 to 4B, the contact plug 170Fa may include a barrierlayer BM, and a conductive layer CM.

In the semiconductor device 100 a in the example embodiment of thepresent inventive concepts, both sides of the contact plug 170Fa of onthe upper portion of the source/drain regions 110 may have step portionsSTa and STb having a step shape. Both sides of the contact plug 170Famay be step-shaped in reverse toward the substrate 101, by the stepportions STa and STb.

The step portions STa and STb may be located outwardly of thesource/drain regions 110. The step portions STa and STb may have thesame shape as each other or have different shapes. For example, in thestep portions STa and STb, the length of step surfaces SPa and SPb, andthe gradients of the sides of the contact plug 170Fa on the upper andlower portions of the step surfaces SPa and SPb may be the same as ordifferent from each other. The contact plug 170Fa may also be regardedas having at least one side that comprises a plurality of line segmentsLS, when viewed in cross-section.

The wiring line 180F is illustrated as being connected to the contactplug 170Fa only on one side of the contact plug 170Fa, but is notlimited thereto. For example, an additional wiring line 180F may bedisposed on the right side of the contact plug 170Fa.

Referring to FIG. 5 , a semiconductor device 100 b may include asubstrate 101, active fins 105, source/drain regions 110, a gatestructure 140, a contact plug 170Fb, and a wiring line 180F. Thesemiconductor device 100 b may further include isolation layers 107 andan interlayer insulating layer 160.

In the semiconductor device 100 b in the example embodiment of thepresent inventive concepts, both sides of the contact plug 170Fb on theupper portion of the source/drain regions 110 may have step portions STaand STc having a step shape. Of the step portions STa and STc, the stepportion STa on the left side in FIG. 5 may be formed so that a width ofthe contact plug 170Fb may widen toward the upper portion thereof in thez direction, and the step portion STc on the right side in FIG. 5 may beformed so that a width thereof may narrow. Thus, the left side of thecontact plug 170Fb may be step-shaped in reverse toward the substrate101, and the right side thereof may be step-shaped by the step portionsSTa and STc. The step portion STa on the left side of the contact plug170Fb may be located outwardly of the source/drain regions 110, and thestep portion STc on the right side may be located above the source/drainregions 110. Lengths of the step surfaces SPa and SPc may be the same ordifferent from each other. For example, the length of the step surfaceSPc on the right side may be greater than the length of the step surfaceSPa on the left side.

In the example embodiment of the present inventive concepts, the stepportions STa and STc may be formed on the left and right sides of thecontact plug 170Fb as described above in a direction of expanding and adirection of decreasing the width of the contact plug 170Fbrespectively, allowing for a volume and a cross-sectional area of aplane in x-z directions of the contact plug 170Fb to be reduced. Sincethe cross-sectional area of the plane in x-z directions of the contactplug 170Fb decreases, a parasitic capacitance between the contact plug170Fb and the first and second gate electrodes 145 and 147 (see FIG. 2 )may be reduced. The contact plug 170Fb may also be regarded as having atleast one side that comprises a plurality of line segments LS, whenviewed in cross-section.

The wiring line 180F may be connected to the contact plug 170Fb on theupper portion of the step portion STa on the left side.

Referring to FIG. 6 , a semiconductor device 100 c may include asubstrate 101, active fins 105, source/drain regions 110, a gatestructure 140, a contact plug 170Fc, and a wiring line 180F. Thesemiconductor device 100 c may further include isolation layers 107 andan interlayer insulating layer 160.

In the semiconductor device 100 c in the example embodiment of thepresent inventive concepts, both sides of the contact plug 170Fc on theupper portion of the source/drain regions 110 may have step portionsSTd1, STd2, STe1, and STe2 having a step shape, respectively. Aplurality of step portions STd1, STd2, STe1, and STe2 may be formed on asingle side of the contact plug 170Fc. The step portions STd1 and STd2on the left side of the contact plug 170Fc may be formed so that thewidth of the contact plug 170Fc may widen toward the upper portion inthe z direction, and the step portions STe1 and STe2 on the right sidemay be formed so that the width thereof may narrow. Thus, the stepportions STd1 and STd2 on the left side may be located outwardly of thesource/drain regions 110, and the step portions STe1 and STe2 on theright side may be located above the source/drain regions 110. The lengthof the step surfaces may be the same or different from each other. Thecontact plug 170Fc may also be regarded as having at least one side thatcomprises a plurality of line segments LS, when viewed in cross-section.

The example embodiment of the present inventive concepts illustrates twostep portions STd1, STd2, Ste1, and Ste2 being formed on the left sideand the right side of the contact plug 170Fc, respectively, but thenumber of step portions is not limited thereto, and may be selected invarious ways. The numbers of the step portions STd1, STd2, Ste1, andSte2 formed on the left side and the right side of the contact plug170Fc, respectively, may also be different from each other.

In the example embodiment of the present inventive concepts, a pluralityof step portions STd1, STd2, Ste1, and Ste2 may be formed on the leftand right sides of the contact plug 170Fc, respectively, as describedabove, allowing a more detailed shape of the contact plug 170Fc.

The wiring line 180F may be connected to the contact plug 170Fc on theupper portion of the step portions STd1 and STd2 on the left side of thecontact plug 170Fc.

Referring to FIG. 7 , a semiconductor device 100 d may include asubstrate 101, active fins 105, source/drain regions 110, a gatestructure 140, a contact plug 170Fd, and a wiring line 180F. Thesemiconductor device 100 d may further include isolation layers 107 andan interlayer insulating layer 160.

In the semiconductor device 100 d of the example embodiment of thepresent inventive concepts, the maximum length L8 of the contact plug170Fd in an x direction may be shorter than the maximum length L7 of thesource/drain regions 110. One ends on the left side of the contact plug170Fd may be extended outwardly from one end of the source/drain regions110, and other ends on the right side of the contact plug 170Fd may belocated above the source drain regions 110. Thus, the contact plug 170Fdbe on, and in some embodiments may cover, only a portion of the uppersurface of the source/drain regions 110. The contact plug 170Fd may alsobe regarded as having at least one side that comprises a plurality ofline segments LS, when viewed in cross-section.

In the example embodiment of the present inventive concepts, the contactplug 170Fd may be formed on, and in some embodiments to cover, only aportion of the upper surface of the source/drain regions 110 asdescribed above, allowing for a volume and a cross-sectional area in theplane x to z of the contact plug 170Fd to be reduced. Thus, a parasiticcapacitance between the contact plug 170Fd and the first and second gateelectrodes 144 and 147 (see FIG. 2 ) may be reduced. However, sinceresistance may increase according to the reduction of the volume of thecontact plug 170Fd, the size of the contact plug 170Fd may be determinedin consideration of the material of the contact plug 170Fd and thedesired contact resistance.

The contact plug 170Fd may have step-shaped step portions STf and STg onboth sides on the upper portion of the source/drain regions 110. Of thestep portions STf and STg, the step portion STf on the left side may beformed so that the width of the contact plug 170Fd may widen toward theupper portion in the z direction, and the step portion STg on the rightside may be formed so that the width may narrow. The length of the stepsurfaces may be the same or different from each other. In addition, theside of the contact plug 170Fd may be perpendicular to the substrate101, forming step portions STf and STg in a perpendicular form. However,the example embodiment of the present inventive concepts is not limitedthereto, and the side of the contact plug 170Fd may be formed to have adesired gradient.

The wiring line 180F may be connected to the contact plug 170Fd on theupper portion of the step portion STf on the left side.

FIGS. 8 and 9 are perspective views illustrating a semiconductor deviceaccording to example embodiments of the present inventive concepts.

Referring to FIG. 8 , a semiconductor device 100 e may include asubstrate 101, active fins 105, source/drain regions 110 a, a gatestructure 140, and contact plugs 170Fe and 170Se. The semiconductordevice 100 d may further include isolation layers 107.

In the example embodiment of the present inventive concepts, thesource/drain regions 110 a of the semiconductor device 100 e may have ahexagonal shape. The shape of the source/drain regions 110 a may bedetermined by a processing time and thickness or the like in a formingprocess of the source/drain regions 110 a. For example, in a case inwhich the source/drain regions 110 a are formed of an epitaxial layer,the source/drain regions 110 a may have a hexagonal shape by a crystalorientation and the like of the epitaxy as in the example embodiment ofthe present inventive concepts, or may have a pentagonal shape asillustrated in FIG. 2 .

The source/drain regions 110 a may be disposed to be spaced apart fromeach other on the two adjacent active fins 105. The number of activefins 105 intersecting with a single gate structure 140 may be modifiedin various ways according to the example embodiment of the presentinventive concepts.

The contact plugs 170Fe and 170Se may be disposed on the source/drainregions 110 a, and may electrically connect the source/drain regions 110a and the wiring lines 180F and 180S (see FIG. 1 ). The two sides of thecontact plugs 170Fe and 170Se in the x direction may have an asymmetricshape on an upper portion of the source/drain region 110 a. For example,one side may have a perpendicular or an inclined side with respect tothe source/drain regions 110 a, and the other side may have astep-shaped step portion ST.

The contact plugs 170Fe and 170Se may be on, and in some embodiments maycover, at least portions of upper surfaces and sides of the source/drainregions 110 a. In the example embodiment of the present inventiveconcepts, the contact plugs 170Fe and 170Se may be on, and in someembodiments may cover, portions of the upper surface and the inclinedsides of both sides of the upper surfaces in the respective hexagonalarea of the source/drain regions 110 a. The lower surfaces of thecontact plugs 170Fe and 170Se may be located at a second height H2 fromthe upper surface of the substrate 101, between the upper portions ofthe source/drain regions 110 a adjacent to each other in the xdirection. The second height H2 may be modified in various ways within arange of not coming into contact with the upper surface of the substrate101.

Referring to FIG. 9 , a semiconductor device 100 f may include asubstrate 101, active fins 105, a source/drain region 110 a, a gatestructure 140, and contact plugs 170Ff and 170Sf. The semiconductordevice 100 f may further include isolation layers 107.

The source/drain region 110 a may have a hexagonal shape as in theexample embodiment of the present inventive concepts of FIG. 8 . In theexample embodiment of the present inventive concepts, the semiconductordevice 100 f may include only one active fin 105, and the source/drainregion 110 a may be disposed on the active fin 105. The contact plugs170Ff and 170Sf may be on, and in some embodiments may cover, a portionof the upper surface and the inclined sides of both sides of the uppersurfaces of the source/drain region 110 a.

FIGS. 10 to 22B are views illustrating a process sequence to illustratea method of manufacturing a semiconductor device according to exampleembodiments of the present inventive concepts.

Referring to FIG. 10 , trenches TI defining active fins 105 may beformed by patterning a substrate 101.

First, a pad oxide pattern 122 and a mask pattern 124 may be formed onthe substrate 101. The pad oxide pattern 122 may be a layer protectingthe upper surface of the active fins 105, and may be omitted accordingto an example embodiment of the present inventive concepts. The maskpattern 124 may be a mask layer patterning the substrate 101, and mayinclude silicon nitride and/or a carbon-containing material, and thelike. The mask pattern 124 may be formed of a multi-layer structure.

The trenches TI may be formed by anisotropic etching of the substrate100 using the pad oxide pattern 122 and the mask pattern 124. Since thetrenches TI may have high aspect ratios, widths thereof may graduallynarrow toward the lower portion; thereby, the active fins 105 may have ashape of narrowing towards the upper portion thereof.

Referring to FIG. 11 , an isolation layer 107 in, and in someembodiments filling, the trenches TI may be formed.

First, processes of filling the trenches TI with an insulating materialand planarization may be performed. At least portions of the pad oxidepattern 122 and the mask pattern 124 may be removed during theplanarization process. In another example embodiment of the presentinventive concepts, the trenches TI may be filled after first forming arelatively thin liner layer within the trenches TI.

Next, by removing a portion of the insulating material for filling thetrenches TI, a process of projecting the active fins 105 from thesubstrate 101 may be performed. This process may be performed, forexample, as a wet etching process using at least a portion of the padoxide pattern as an etching mask. As a result, the active fins 105 maybe projected by a height H3 toward the upper portion, and the projectingheight H3 may be modified in various ways. During the etching process,the pad oxide pattern 122 may also be removed.

Referring to FIG. 12 , a dummy gate insulating layer 132 and a dummygate electrode 135 extended by intersecting active fins 105 may beformed.

The dummy gate insulating layer 132 and the dummy gate electrode 135 maybe formed, for example, by performing an etching process using a maskpattern layer 136.

The dummy gate insulating layer 132 and the dummy gate electrode 135 maybe formed on a region where the gate insulating layer 142 and the firstand second gate electrodes 145 and 147 (see FIG. 2 ) are to be formed,and may be removed during a subsequent process. For example, the dummygate insulating layer 132 may include silicon oxide, and the dummy gateelectrode 135 may include polysilicon.

Referring to FIG. 13 , a spacer 144 may be formed on both sides of adummy gate insulating layer 132, a dummy gate electrode 135, and a maskpattern layer 136. Next, active fins 105 on both sides of the spacer 144may be selectively removed.

The spacer 144 may be formed by forming a film having a uniformthickness on the upper portion of the dummy gate insulating layer 132,the dummy gate electrode 135, and the mask pattern layer 136, and byanisotropically etching of the film.

Recesses may be formed by removing the active fins 105 from both sidesof the spacer 144. The recesses may be formed by etching portions of theactive fins 105 by forming a separate masking layer or using the maskpattern layer 136 and the spacer 144 as a mask. The recess may beformed, for example, by sequentially applying a dry etching process anda wet etching process thereto. Selectively, after the formation of therecesses, a process of curing the surfaces of the recessed active fins105 may be performed by a separate process. In the example embodiment ofthe present inventive concepts, the upper surfaces of the recessedactive fins 105 are illustrated as being at the same level as the uppersurface of the isolation layer 107, but are not limited thereto. Inanother example embodiment of the present inventive concepts, the uppersurface of the recessed active fins 105 may be higher or lower than theupper surface of the isolation layer 107.

Before or after the formation of the recesses, a process of implantingimpurities in the active fins 105 on both sides of the dummy gateelectrode 135 may be performed. The process of implanting impurities maybe performed using the mask pattern layer 136 and the spacer 144 as amask.

Referring to FIG. 14 , a source/drain region 110 may be formed onrecessed active fins 105 on both sides of the spacer 144.

The source/drain region 110 may be formed, for example, using aselective epitaxial growth (SEG) process. The source/drain region 110may have a pentagonal or a hexagonal shape as illustrated by growingalong a crystallographically stable surface in a growth process.However, the size and shape of the source/drain region 110 are notlimited to the illustration.

The source/drain region 110 may be, for example, a silicon germanium(SiGe) layer. In a case in which SiGe is grown on active fins 105 formedof silicon (Si), compressive stress may be generated in a channel regionof the semiconductor device. Such a compressive stress may be increasedas a concentration of germanium (Ge) increases. In some exampleembodiments of the present inventive concepts, the concentration of Gewithin the source/drain region 110 may be formed differently accordingto the height.

The source/drain region 110 may contain impurities. The impurities maybe contained by in-situ implantation of ions during growth of thesource/drain region 110 and/or by a separate implantation of ions aftergrowth. The grown source/drain region 110 may be provided as a sourceregion or a drain region of the semiconductor device.

Referring to FIG. 15 , a first interlayer insulating layer 162 may beformed on a source/drain region 110.

The first interlayer insulating layer 162 may be formed by forming alayer on, and in some embodiments covering, a mask pattern layer 136, aspacer 144, and a source/drain region 110 with an insulating material,and by allowing the upper surface of a dummy gate electrode 135 to beexposed through a planarization process. Thus, the mask pattern layer136 may be removed during this process.

The first interlayer insulating layer 162 may include, for example, atleast one oxide, nitride and/or oxynitride.

Referring to FIG. 16 , a dummy gate insulating layer 132 and a dummygate electrode 135 may be removed.

The dummy gate insulating layer 132 and the dummy gate electrode 135 maybe selectively removed with respect to an isolation layer 107 and activefins 105 of the lower portion, and an opening E exposing the isolationlayer 107 and the active fins 105 may be formed.

The removal process of the dummy gate insulating layer 132 and the dummygate electrode 135 may be through at least one of a dry etching processand/or a wet etching process.

Referring to FIG. 17 , a gate structure 140 may be formed by forming agate insulating layer 142 and first and second gate electrodes 145 and147 within the opening E.

The gate insulating layer 142 may be formed substantially in a conformalmanner along the sidewalls and the lower surface of the opening E. Thegate insulating layer 142 may include an oxide, a nitride and/or ahigh-k material.

The first and second gate electrodes 145 and 147 may include a metal ora semiconductor material.

FIGS. 18A to 22B illustrate a perspective view along with a crosssection cut along line X-X′.

Referring to FIGS. 18A and 18B, a second interlayer insulating layer 164on, and in some embodiments covering, the first and second gateelectrodes 145 and 147 and a source/drain region 110, and a first masklayer 192 having a first open region P1, may be formed.

The second interlayer insulating layer 164 may include, for example, atleast one oxide, nitride and/or oxynitride. The second interlayerinsulating layer 164 may be formed of the same material as the firstinterlayer insulating layer 162.

The first mask layer 192 may be a layer for patterning the first andsecond insulating layers 162 and 164. The first mask layer 192 may be,for example, a photoresist layer. The first mask layer 192 may exposethe second interlayer insulating layer 164 through a first open regionP1. The length of the first open region P1 in an extending direction ofthe first and second gate electrodes 145 and 147 may be shorter than alength L4 (see FIG. 1 ), the length of the contact plugs 170F and 170S.

Referring to FIGS. 19A and 19B, first and the second interlayerinsulating layers 162 and 164 may be patterned using the first masklayer 192.

A first etching region OP1 may be formed by removing the secondinterlayer insulating layer 164 exposed through the first open regionP1, and removing the first interlayer insulating layer 162 exposed afterremoving the second interlayer insulating layer 164.

The first etching region OP1 may be formed to have a predetermined depthD3 from the upper surface of the second interlayer insulating layer 164.The depth D3 of the first etching region OP1 may be less than the depthto the source/drain region 110, but is not limited thereto, and may bemodified in various ways.

Referring to FIGS. 20A and 20B, a second mask layer 194 having a secondopen region P2 may be formed.

The second mask layer 194 may be a layer for patterning the first andsecond interlayer insulating layers 162 and 164. The second mask layer194 may be, for example, a photoresist layer. The second mask layer 194may expose portions of the first etching region OP1 and the secondinterlayer insulating layer 164 adjacent to the first etching region OP1through the second open region P2. The length of the second open regionP2 in an extending direction of the first and second gate electrodes 145and 147 may be substantially the same as the length L4 (see FIG. 1 ),the length of the contact plugs 170F and 170S.

In an example embodiment of the present inventive concepts, the secondmask layer 194 may not be a layer separate from the above-mentionedfirst mask layer 192 with reference to FIGS. 18A and 18B, but may be alayer formed by enlarging the first open region P1 of the first masklayer 192 using a trimming process.

For example, the semiconductor device 100 a as described above withreference to FIG. 4 may be manufactured using such a trimming process.In this case, in the contact plug 170Fa, the second region of the upperportion of the step surfaces Spa and SPb may have a width expanded alsoin the y-direction, not illustrated, further than the width of the firstregion of the lower portion. The semiconductor device 100 a of theexample embodiment of the present inventive concepts in FIG. 4 , in thiscase, may be formed by adjusting the location and width of the secondopen region P2. In detail, the semiconductor device 100 a having stepportions formed on both sides of the device as illustrated in FIG. 4 maybe manufactured by the second open region P2 in FIG. 20B being formed toexpose the second interlayer insulating layer 164 on the right side aswell.

Referring to FIGS. 21A and 21B, first and second interlayer insulatinglayers 162 and 164 may be patterned using a second mask layer 194.

A second etching region OP2 may be formed by removing the exposed firstand second interlayer insulating layers 162 and 164 through a secondopen region P2. At least a portion of the upper and side surfaces of thesource/drain region 110 may be exposed through the second etching regionOP2. A portion of the exposed source/drain region 110 from the uppersurface may be removed during an etching process, and a portion of theupper surface may have a curved surface from being etched asillustrated. The second etching region OP2 may be an expanded region ofthe first etching region OP1, and a step portion may be formed betweenthe region where the first etching region OP1 was formed and thesurrounding regions. The height of the step portion may vary dependingon the relative etched depths in the first and the second etchingregions OP1 and OP2.

In the example embodiment of the present inventive concepts,over-etching of the first interlayer insulating layer 162 to the sidesof the source/drain region 110 during an etching process may be reducedor prevented, by sequentially forming the first and second etchingregions OP1 and OP2 having different sizes from each other through twoetching processes, compared to forming an opening exposing the uppersurface of the source/drain region 110 in just one process. Therefore,since the etched depth may be easily adjusted, the contact plugs 170Fand 170S may be controlled so that the depth thereof may not be formedunnecessarily deeply or extended to the substrate 101 in the rear.

Referring to FIGS. 22A and 22B, contact plugs 170F and 170S may beformed by providing a conductive material in, and in some embodimentsfilling, a second etching region OP2.

The contact plug 170F, for convenience of explanation, may bedistinguished as a first region 170F1 of the lower portion, and a secondregion 170F2 of the upper portion, based on the step portion. The stepportion may be formed by the second region 170F2 being extended longerthan the first region 170F1 from one side of the contact plug 170F. Inthe formation of the contact plug 170F, first, a barrier layer BM may beformed, and a conductive layer CM may be formed on the barrier layer BM.The contact plug 170F may also be regarded as having at least one sidethat comprises a plurality of line segments LS, when viewed incross-section.

Next, with reference to FIG. 3A, wiring lines 180F crossing one side ofthe contact plugs 170F may be formed. By the step portion, the contactplugs 170F may be stably connected to the wiring lines 180F by beingextended outwardly of the source/drain region 110 in one direction.

FIGS. 23 to 26 are views illustrating a process sequence to illustrate amethod of manufacturing a semiconductor device according to exampleembodiments of the present inventive concepts. FIGS. 23 to 26 illustrateprocesses after the above-described processes with reference to FIGS. 10to 17 .

Referring to FIG. 23 , a first mask layer 192′ may be formed, and afirst interlayer insulating layer 162 may be patterned using the firstmask layer 192′.

The first interlayer insulating layer 162 on the source/drain region 110may be exposed by the first mask layer 192′. Thus, a first etchingregion OP1′ may be formed by removing the exposed first interlayerinsulating layer 162. The source/drain region 110 may be exposed throughthe first etching region OP1′.

Referring to FIG. 24 , a first region 170Fb1 of the contact plug 170Fb(see FIG. 5 ) may be formed by providing a conductive material in, andin some embodiments filling, a first etching region OP1′. The firstregion 170Fb1 may include a barrier layer BM and a conductive layer CM.The barrier layer BM may be formed first. Afterwards, the conductivelayer CM may be formed, and the barrier layer BM may be formed again onthe upper surface of the conductive layer CM.

Next, a second interlayer insulating layer 164′ on, and in someembodiments covering, the first region 170Fb1 may be formed. Asnecessary, prior to the formation of the second interlayer insulatinglayer 164′, a flattening process may be further performed.

Referring to FIG. 25 , a second interlayer insulating layer 164′ may bepatterned using a second mask layer 194′.

A second etching region OP2′ may be formed by removing the secondinterlayer insulating layer 164′ exposed by the second mask layer 194′.The second etching region OP2′ may expose a first region 170Fb1 of thecontact plug 170Fb.

The second etching region OP2′ may expose a portion of the first region170Fb1, and may be formed to be shifted toward one direction based on asource/drain region 110. In one example embodiment of the presentinventive concepts, a barrier layer BM exposed through the secondetching region OPT may also be at least partially removed.

Referring to FIG. 26 , a second region 170Fb2 of a contact plug 170Fbmay be formed by filling a second etching region OPT with a conductivematerial.

The second region 170Fb2 may include a barrier layer BM and a conductivelayer CM. The barrier layer BM may be formed first, and the conductivelayer CM may be formed afterwards. In detail, the barrier layer BM maybe prevented from forming on the upper surface of a first region 170Fb1where the second region 170Fb2 is formed, or may be removed afterformation. However, the shape and disposition of the barrier layer BMare not limited thereto, and may be modified in various ways.

Thereby, a contact plug 170Fb including the first and second regions170Fb1 and 170Fb2 may be formed. Step portions may be formed on bothsides of the contact plug 170Fb above the source/drain region 110. Oneof the step portions may be formed to narrow toward a substrate 101, andthe other may be formed to widen. The contact plug 170Fb may also beregarded as having at least one side that comprises a plurality of linesegments LS, when viewed in cross-section.

Next, with reference to FIG. 5 , a wiring line 180F passing one side ofthe contact plug 170Fb may be formed. The contact plug 170F may bestably connected to the wiring line 180F by being extended outwardly ofthe source/drain region 110 in one direction while securing a contactregion with the source/drain region 110 by the step portions.

Using the above-mentioned manufacturing method with reference to FIGS.23 to 26 , semiconductor devices 100 c and 100 d of FIGS. 6 and 7 of theexample embodiment of the present inventive concepts may bemanufactured. For example, the semiconductor device 100 c of FIG. 6 maybe manufactured by carrying out the process described above withreference to FIGS. 25 and 26 once more. The semiconductor device 100 dof FIG. 7 may be manufactured by controlling an etching process so thatthe side surface thereof may be etched perpendicularly, and by adjustingan etching region during the formation of first and a second etchingregions OP1′ and OPT.

FIGS. 27 to 28B are a top view and a cross-sectional view of asemiconductor device according to an example embodiment of the presentinventive concepts. FIGS. 28A and 28B illustrate a section along linesA-A′ and B-B′ in FIG. 27 , respectively.

Referring to FIGS. 27 to 28B, the semiconductor device 200 may include asubstrate 201, an active region 205 extending in a first direction, forexample, an x-direction on the substrate 201, source/drain regions 210on the active region 205, a gate structure 240 extending in a seconddirection, for example, a y-direction, and contact plugs 270F and 270S.The semiconductor device 200 may further include isolation layers 207and an interlayer insulating layer 260.

The semiconductor device 200 of the example embodiment of the presentinventive concepts may be a planar transistor having a flat uppersurface without the active region 205 being projected toward the gatestructure 240, unlike the semiconductor device 100 of FIGS. 1 to 3B.

The substrate 201 may have an upper surface extending in x and ydirections. The substrate 201 may include a semiconductor material, suchas a group IV semiconductor material, a group III-V compoundsemiconductor material, or a group II-IV oxide semiconductor material.

The isolation layers 207 may be formed of an insulating material. Theisolation layers 207 may be formed of, for example, an oxide, a nitride,or a combination of both. The active area 205 may be defined by theisolation layers 207 in the substrate 201. The active region 205 may berecessed and the source/drain regions 210 may be disposed on the sidesurface of the gate structure 240.

The source/drain regions 210 may be disposed on the active region 205from both sides of the gate structure 240. The source/drain regions 210may be in an elevated source/drain form in which the upper surface ofthe source/drain regions 210 is located higher than the lower surface ofthe gate structure 240. The source/drain regions 210 may be provided assource/drain regions of the semiconductor device 200. However, thesource/drain regions 210 in the present inventive concepts are notlimited to the elevated form, and in other example embodiments of thepresent inventive concepts, the source/drain regions 210 of thesemiconductor device 200 may be formed as impurity regions within theactive region 205.

The gate structure 240 may disposed to intersect the active region 205on the upper portion of the active region 205, and may include a gateinsulating layer 242, a gate electrode 245, and spacers 244. The gateinsulating layer 242 may be formed of an oxide, a nitride and/or anoxynitride. The gate electrode 245 may include a metal, a metal nitrideand/or a doped polysilicon. The spacers 244 may be disposed on bothsides of the gate electrode 245. The spacer 244 may be formed of anoxide, a nitride, or an oxynitride, and may be formed of a multi-layerfilm.

An interlayer insulating layer 260 may be disposed on, and in someembodiments to cover, the substrate 201, the source/drain regions 210and the gate structure 240. The interlayer insulating layer 260 may beformed of an insulating material, such as at least one of an oxide film,a nitride film, and an oxynitride film.

The contact plugs 270F and 270S may be disposed on the source/drainregions 210, and may electrically connect the source/drain regions 210and a wiring structure of the upper portion by penetrating theinterlayer insulating layer 260. One ends of the contact plugs 270F and270S may be extended outwardly of the source/drain regions 210 by apredetermined length D4 in the y-direction from one ends of thesource/drain regions 210. The length D4 may be determined according tothe disposition of the wiring structure. The contact plugs 270F and270S, by such a structure, may be connected to the wiring structurewhich is spaced apart in the y-direction from the source/drain regions210.

The contact plugs 270F and 270S may have an extended shape in anextended direction of the gate structure 240, for example, in they-direction, and may have a rectangular shape, an oval shape, or thelike. A ninth length L9, a length in the x direction, may be shorterthan a tenth length L10, a length in the y-direction. For example, thetenth length L10 may be three times longer or more than the ninth lengthL9.

The two sides of the contact plugs 270F and 270S may have an asymmetricshape in the y-direction above the source/drain regions 210. Forexample, one side of the contact plugs 270F and 270S may have a sideperpendicular to the source/drain regions 210, or may be continuouslyextended having a gradient, and another side of the contact plugs 270Fand 270S may have a step-shaped step portion ST. The step portion ST maybe located outwardly of the source/drain regions 210. The step portionST may include a step surface SP being perpendicular to the uppersurface of the substrate 201 or having a gradient. The step surface SPmay be located outwardly of the source/drain regions 210 in they-direction. The contact plugs 270F and 270S may also be regarded ashaving at least one side that comprises a plurality of line segments LS,when viewed in cross-section.

The contact plugs 270F and 270S may be on, and in some embodimentscover, portions of the upper and side surfaces of the source/drainregions 210. However, the example embodiment of the present inventiveconcepts is not limited thereto, and in other example embodiments of thepresent inventive concepts, the contact plugs 270F and 270S may be on,and in some embodiments may cover, only the upper surface of thesource/drain regions 210.

The contact plugs 270F and 270S may include a conductive material suchas aluminum (Al), copper (Cu), tungsten (W) and/or the like.

FIG. 29 is a circuit diagram of an SRAM cell including a semiconductordevice according to example embodiments of the present inventiveconcepts.

Referring to FIG. 29 , a cell in SRAM elements may include first andsecond drive transistors TN1 and TN2, first and second load transistorsTP1 and TP2, and first and second access transistors TN3 and TN4. Here,a source of the first and second drive transistors TN1 and TN2 may beconnected to a ground voltage line Vss, and a source of the first andsecond load transistors TP1 and TP2 may be connected to a power supplyvoltage line Vdd.

The first drive transistor TN1 including a NMOS transistor and thesecond load transistor TP1 including a PMOS transistor may provide afirst inverter, and the second drive transistor TN2 including a NMOStransistor and the second load transistor TP2 including a PMOStransistor may provide a second inverter. The first and/or second drivetransistors TN1 and/or TN2, the first and/or second load transistors TP1and/or TP2, and/or the first and/or second access transistors TN3 and/orTN4 may include the semiconductor device according to various exampleembodiments of the present inventive concepts as described above withreference to FIGS. 1 to 9 and FIGS. 27 to 28B.

An output terminal of the first and second inverters may be connected tothe source of the first access transistor TN3 and the second accesstransistor TN4. Further, an input terminal and the output terminal ofthe first and second inverters may be connected by intersecting eachother to configure a single latch circuit. Also, a drain of the firstand second access transistors TN3 and TN4 may be connected to first andsecond bit lines BL and/BL, respectively.

FIG. 30 is a block diagram illustrating a storage device including asemiconductor device according to example embodiments of the presentinventive concepts.

Referring to FIG. 30 , a storage device 1000 according to the exampleembodiment of the present inventive concepts may include a controller1010 communicating with a host, and memories 1020-1, 1020-2, and 1020-3storing data. Each memory 1020-1, 1020-2 and/or 1020-3, and/or thecontroller 1010 may include the semiconductor device according tovarious example embodiments of the present inventive concepts asdescribed above with reference to FIGS. 1 to 9 and FIGS. 27 to 28B.

The host communicating with the controller 1010 may be a variety ofelectronic devices provided with the storage device 1000, for example, asmart phone, a digital camera, a desktop computer, a laptop computer, amedia player, or the like. The controller 1010 may receive and storewriting data or read requests transmitted from the host to the memories1020-1, 1020-2, and 1020-3, or may generate a command to retrieve datafrom the memories 1020-1, 1020-2, and 1020-3.

As illustrated in FIG. 30 , one or more of the memories 1020-1, 1020-2,and 1020-3 may be connected in parallel to the controller 1010 in thestorage device 1000. By connecting a plurality of memories 1020-1,1020-2, and 1020-3 in parallel to the controller 1010, the storagedevice 1000 having a large capacity such as an SSD (Solid State Drive)may be realized.

FIG. 31 is a block diagram illustrating an electronic apparatusincluding a semiconductor device according to example embodiments of thepresent inventive concepts.

Referring to FIG. 31 , an electronic device 2000, according to theexample embodiment of the present inventive concepts, may include acommunication unit 2010, an input unit 2020, an output unit 2030, amemory 2040, and a processor 2050.

The communication unit 2010 may include a wired/wireless communicationmodule, and a wireless internet module, a short-range communicationmodule, a GPS module and/or a mobile communication module. Thewired/wireless communication module included in the communication unit2010 may transmit and receive data by being connected to an externalcommunication network by a variety of communications standards.

The input unit 2020 is a module provided for the user to controloperations of the electronic device 2000, and may include a mechanicalswitch, a touch screen, a voice recognition module and/or the like.Further, the input unit 2020 may include a mouse operating in atrackball and/or a laser pointer method and the like and/or a fingermouse device, and may further include a variety of sensor modulesallowing the user to input data.

The output unit 2030 may output information processed by the electronicdevice 2000 in the form of sound and/or video, and the memory 2040 maystore a program for process and control of the processor 2050, or data.The processor 2050 may store or retrieve data by transmitting a commandto the memory 2040 according to the required action.

The memory 2040 may be provided in the electronic device 2000 or maycommunicate with the processor 2050 via a separate interface. Whencommunicating with the processor 2050 via a separate interface, theprocessor 2050 may store or retrieve data from the memory 2040 via avariety of interface standards, such as SD, SDHC, SDXC, MICRO SD and/orUSB.

The processor 2050 may control operations of each unit included in theelectronic device 2000. The processor 2050 may perform control andprocesses related to voice calling, video calling, data communicationsand/or the like, and/or may also perform control and processes formultimedia playback and management. Further, the processor 2050 mayprocess input transmitted from the user via the input unit 2020, and mayoutput the results via the output unit 2030. In addition, the processor2050, as previously described, may store data necessary in controllingthe operation of the electronic device 2000 in the memory 2040, orretrieve the data from the memory 2040. The processor 2050, the memory2040 and/or any of the other units of FIG. 31 may include thesemiconductor device according to various example embodiments of thepresent inventive concepts as described above with reference to FIGS. 1to 9 and FIGS. 27 to 28B.

FIG. 32 is a schematic diagram illustrating a system including asemiconductor device according to example embodiments of the presentinventive concepts.

Referring to FIG. 32 , a system 3000 may include a controller 3100, aninput/output device 3200, a memory 3300 and an interface 3400. Thesystem 3000 may be a mobile system and/or a system transmitting and/orreceiving information. The mobile system may be a PDA, a portablecomputer, a web tablet, a wireless phone, a mobile phone, a digitalmusic player and/or a memory card.

The controller 3100 may run a program and/or control the system 3000.The controller 3100 may be, for example, a microprocessor, a digitalsignal processor, a microcontroller and/or a similar device.

The input/output device 3200 may be used to input or output data of thesystem 3000. The system 3000 may be connected to an external device,such as a personal computer and/or a network using the input/outputdevice 3200, and may exchange data with the external device. Theinput/output device 3200 may be, for example, a keypad, a keyboardand/or a display device.

The memory 3300 may store a code and/or data for the operation of thecontroller 3100, and/or may store data processed by the controller 3100.The memory 3300 and/or any of the other blocks of FIG. 32 may includethe semiconductor device according to any one of the example embodimentsof the present inventive concepts.

The interface 3400 may be a data transmission path between the system3000 and other external devices. The interface 3400 may communicate withthe controller 3100, the input/output device 3200, and the memory 3300via a bus 3500.

The controller 3100, the memory 3300 and/or any of the other blocks ofFIG. 32 may include at least one of the semiconductor devices accordingto various example embodiments of the present inventive concepts asdescribed above with reference to FIGS. 1 to 9 and FIGS. 27 to 28B.

As set forth above, by forming step portions on sides of contact plugs,a semiconductor device may have improved degree of integration andreliability, and a method of manufacturing the same may also beprovided.

While example embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinventive concepts as defined by the appended claims.

What is claimed is:
 1. A method of manufacturing a semiconductor devicecomprising: forming an isolation layer defining an active fin, whereinthe active fin has a shape extending in a first direction; forming asource/drain epitaxial layer on the active fin; forming an insulatingstructure on the isolation layer and the source/drain epitaxial layer;forming a first mask layer having a first open region and on theinsulating structure; forming a preliminary opening by etching an upperportion of the insulating structure using the first mask layer as afirst etching mask, wherein the preliminary opening overlaps thesource/drain epitaxial layer in a vertical direction; removing the firstmask layer; forming a second mask layer having a second open region andon the insulating structure, wherein the second open region has a firstregion overlapping at least a portion of the preliminary opening in thevertical direction and a second region not overlapping the preliminaryopening in the vertical direction; forming an opening exposing thesource/drain epitaxial layer by etching the insulating structure usingthe second mask layer as a second etching mask; removing the second masklayer; and forming a contact plug contacting and in the opening, whereinthe opening includes: a lower open region exposing the source/drainepitaxial layer; and an upper open region at a higher level than thelower open region, wherein the contact plug includes: a lower plugregion in the lower open region and contacting the source/drainepitaxial layer; and an upper plug region in the upper open region andextending from the lower plug region.
 2. The method of manufacturing asemiconductor device of claim 1, wherein a maximum width of thesource/drain epitaxial layer in a second direction is greater than aminimum width of the lower open region in the second direction, andwherein the second direction is perpendicular to the first direction. 3.The method of manufacturing a semiconductor device of claim 2, wherein awidth of the upper plug region in the second direction is greater than awidth of the lower plug region in the second direction.
 4. The method ofmanufacturing a semiconductor device of claim 1, wherein an entirebottom surface of the lower plug region contacts the source/drainepitaxial layer.
 5. The method of manufacturing a semiconductor deviceof claim 1, wherein the upper plug region includes: a first portionextending from the lower plug region in the vertical direction; and asecond portion extending from the first portion in a second directionperpendicular to the first direction, and wherein the second portion ofthe upper plug region does not overlap with the source/drain epitaxiallayer in the vertical direction.
 6. The method of manufacturing asemiconductor device of claim 5, further comprising: forming a wiringline on the insulating structure and the contact plug, and wherein thewiring line extends in the first direction.
 7. The method ofmanufacturing a semiconductor device of claim 6, wherein the wiring linecontacts the second portion of the upper plug region.
 8. The method ofmanufacturing a semiconductor device of claim 6, wherein the wiring linedoes not overlap with the source/drain epitaxial layer in the verticaldirection.
 9. The method of manufacturing a semiconductor device ofclaim 1, wherein the insulating structure includes: a first insulatinglayer on a side surface and an upper surface of the source/drainepitaxial layer; and a second insulating layer on the first insulatinglayer, and wherein the preliminary opening passes through the secondinsulating layer.
 10. The method of manufacturing a semiconductor deviceof claim 9, wherein the upper open region passes through the secondinsulating layer, and wherein the lower open region passes through thefirst insulating layer on the upper surface of the source/drainepitaxial layer.
 11. A method of manufacturing a semiconductor devicecomprising: forming an isolation layer defining an active fin on asubstrate, wherein the active fin has a shape extending in a firstdirection; forming a dummy gate pattern on a first active region of theactive fin and the isolation layer, wherein the dummy gate patternextends in a second direction perpendicular to the first direction;forming a source/drain epitaxial layer on a second active region of theactive fin; forming a first insulating layer on source/drain epitaxiallayer and the isolation layer and a side surface of the dummy gatepattern; forming a gate trench by removing the dummy gate pattern;forming a gate structure in the gate trench; forming a second insulatinglayer on the first insulating layer and the gate structure; forming afirst mask layer having a first open region and on the second insulatinglayer; forming a preliminary opening by etching the second insulatinglayer using the first mask layer as a first etching mask, wherein thepreliminary opening overlaps the source/drain epitaxial layer in avertical direction; removing the first mask layer; forming a second masklayer having a second open region and on the second insulating layer,wherein the second open region has a first region overlapping at least aportion of the preliminary opening in the vertical direction and asecond region not overlapping the preliminary opening in the verticaldirection; forming an opening exposing the source/drain epitaxial layerby etching the first and second insulating layers using the second masklayer as a second etching mask; removing the second mask layer; andforming a contact plug contacting and in the opening, wherein theopening includes: a lower open region exposing the source/drainepitaxial layer; and an upper open region at a higher level than thelower open region, wherein the contact plug includes: a lower plugregion in the lower open region and contacting the source/drainepitaxial layer; and an upper plug region in the upper open region andextending from the lower plug region.
 12. The method of manufacturing asemiconductor device of claim 11, wherein a width of the upper plugregion in the second direction is greater than a width of the lower plugregion in the second direction, and wherein an entire bottom surface ofthe lower plug region contacts the source/drain epitaxial layer.
 13. Themethod of manufacturing a semiconductor device of claim 11, wherein theupper plug region includes: a first portion extending from the lowerplug region in the vertical direction; and a second portion extendingfrom the first portion in the second direction, and wherein the secondportion of the upper plug region does not overlap with the source/drainepitaxial layer in the vertical direction.
 14. The method ofmanufacturing a semiconductor device of claim 13, further comprising:forming a wiring line on the insulating structure and the contact plug,and wherein the wiring line extends in the first direction.
 15. Themethod of manufacturing a semiconductor device of claim 14, wherein thewiring line contacts the second portion of the upper plug region. 16.The method of manufacturing a semiconductor device of claim 14, whereinthe wiring line does not overlap with the source/drain epitaxial layerin the vertical direction.
 17. A method of manufacturing a semiconductordevice comprising: forming an isolation layer defining an active fin,wherein the active fin has a shape extending in a first direction;forming a source/drain epitaxial layer on the active fin; forming afirst insulating layer on the isolation layer and the source/drainepitaxial layer; forming a first opening passing through the firstinsulating layer and exposing the source/drain epitaxial layer; forminga lower contact plug in the first opening; forming a second insulatinglayer on the first insulating layer and the lower contact plug; forminga second opening passing through the second insulating layer andexposing the lower contact plug and the first insulating layer; andforming an upper contact plug in the second opening, wherein the uppercontact plug includes a first portion contacting the lower contact plugand a second portion contacting the first insulating layer; wherein asecond portion extends from the first portion in a second direction anddoes not overlap with the source/drain epitaxial layer in the verticaldirection, and wherein the second direction is perpendicular to thefirst direction.
 18. The method of manufacturing a semiconductor deviceof claim 17, wherein an entire bottom surface of the lower contact plugcontacts the source/drain epitaxial layer, and wherein an upper surfaceof the lower contact plug includes: a first upper surface contacting alower surface of the first portion; and a second upper surfacecontacting a lower surface of the second insulating layer.
 19. Themethod of manufacturing a semiconductor device of claim 17, furthercomprising: forming a wiring line on the insulating structure and theupper contact plug, and wherein the wiring line extends in the firstdirection.
 20. The method of manufacturing a semiconductor device ofclaim 19, wherein the wiring line contacts the second portion of theupper contact plug, and does not overlap with the source/drain epitaxiallayer in the vertical direction.